Interacting with detail-in-context presentations

ABSTRACT

A method for generating a presentation of a region-of-interest in an original image for display on a display surface, the method comprising: establishing a lens for the region-of-interest, the lens having a focal region with a magnification for the region-of-interest at least partially surrounded by a shoulder region across which the magnification varies to provide a continuous transition from the focal region to regions outside the lens; receiving a first signal for selecting the shoulder region; while receiving the first signal, receiving a second signal for selecting the focal region and for adjusting a position of the focal region relative to the shoulder region to define a degree and a direction of a folding of the focal region over the shoulder region for the lens; and, applying the lens to the original image to produce the presentation.

RELATED APPLICATIONS

This application claims priority as a continuation-in-part from U.S.patent application Ser. No. 11/249,493, filed Oct. 14, 2005 (pending),which claims priority to U.S. Provisional Patent Application No.60/618,249, filed Oct. 14, 2004; and U.S. patent application Ser. No.11/673,038, filed Feb. 9, 2007, which is a continuation of U.S.application Ser. No. 10/137,648, filed May 3, 2002 (now U.S. Pat. No.7,197,719), which claims priority to Canadian Applications 2,350, 342,field Jun. 12, 2001 and 2,345,803, filed May 3, 2001, the entiredisclosures of each of these applications are hereby incorporated byreference.

BACKGROUND

Modem computer graphics systems, including virtual environment systems,are used for numerous applications such as mapping, navigation, flighttraining, surveillance, and even playing computer games. In general,these applications are launched by the computer graphics system'soperating system upon selection by a user from a menu or other graphicaluser interface (“GUI”). A GUI is used to convey information to andreceive commands from users and generally includes a variety of GUIobjects or controls, including icons, toolbars, drop-down menus, text,dialog boxes, buttons, and the like. A user typically interacts with aGUI by using a pointing device (e.g., a mouse) to position a pointer orcursor over an object and “clicking” on the object.

One problem with these computer graphics systems is their inability toeffectively display detailed information for selected graphic objectswhen those objects are in the context of a larger image. A user mayrequire access to detailed information with respect to an object inorder to closely examine the object, to interact with the object, or tointerface with an external application or network through the object.For example, the detailed information may be a close-up view of theobject or a region of a digital map image.

While an application may provide a GUI for a user to access and viewdetailed information for a selected object in a larger image, in doingso, the relative location of the object in the larger image may be lostto the user. Thus, while the user may have gained access to the detailedinformation required to interact with the object, the user may losesight of the context within which that object is positioned in thelarger image. This is especially so when the user must interact with theGUI using a computer mouse or keyboard. The interaction may furtherdistract the user from the context in which the detailed information isto be understood. This problem is an example of what is often referredto as the “screen real estate problem”.

SUMMARY

According to one aspect, there is provided a method for generating apresentation of a region-of-interest in an original image for display ona display surface, the method comprising: establishing a lens for theregion-of-interest, the lens having a focal region with a magnificationfor the region-of-interest at least partially surrounded by a shoulderregion across which the magnification varies to provide a continuoustransition from the focal region to regions outside the lens; receivinga first signal for selecting the shoulder region; while receiving thefirst signal, receiving a second signal for selecting the focal regionand for adjusting a position of the focal region relative to theshoulder region to define a degree and a direction of a folding of thefocal region over the shoulder region for the lens; and, applying thelens to the original image to produce the presentation.

According to another aspect, there is provided a method for generating apresentation of a region-of-interest in an original image for display ona display surface, the method comprising: establishing a lens for theregion-of-interest, the lens having a focal region with a magnificationfor the region-of-interest at least partially surrounded by a shoulderregion across which the magnification varies to provide a continuoustransition from the focal region to regions outside the lens; receivinga first signal for selecting a first point in the focal region; whilereceiving the first signal, receiving a second signal for selecting asecond point in the focal region and for adjusting a position of thesecond point relative to the first point to define a degree and adirection of a rotation for the lens; and, applying the lens to theoriginal image to produce the presentation.

According to another aspect, there is provided a method for selectingpoints spaced apart in an original image presented on a display surface,the method comprising: receiving a first signal for selecting a firstpoint; while receiving the first signal, receiving a second signal forselecting a second point and for adjusting a distance between the secondpoint and the first point in the original image; and, in response to thesecond signal, adjusting a scale and a position of the original image asthe second point approaches a border of the original image as presentedon the display surface to thereby retain presentation of the first andsecond points on the display surface.

According to another aspect, there is provided a method for facilitatinguser access to remote objects on a display surface, the methodcomprising: receiving a drag signal for a local object, the drag signalhaving at least one of an origin and a direction; selecting targetobjects from the remote objects on the display screen according to thedrag signal and at least one of a recency of last use of the targetobjects, a project relationship with the local object, and a similarityof name with the local object; and, temporarily displaying the targetobjects in proximity to the drag signal's origin until a signaldismissing the target objects is received.

According to another aspect, there is provided a method forrepositioning an object in an original image presented on a displaysurface, the method comprising: receiving a first signal for selectingthe object at an original location; while receiving the first signal,receiving a second signal for selecting a direction and a magnitude forthe repositioning of the object; determining a final location for theobject by multiplying the magnitude by a predetermined value greaterthan one; and, moving the object to the final location.

According to another aspect, there is provided a method for generatingan on-screen presentation of an off-screen object in an original imagepresented on a display screen, the method comprising: establishing alens for the off-screen object, the lens having a focal region with amagnification for the off-screen object at least partially surrounded bya shoulder region across which the magnification varies to provide acontinuous transition from the focal region to regions outside the lens;folding the focal region over the shoulder region to position the focalregion within a border of the display screen; applying the lens to theoriginal image to produce the on-screen presentation; and, displayingthe on-screen presentation on the display screen.

In accordance with further aspects there is provided an apparatus suchas a data processing system, a method for adapting this system, as wellas articles of manufacture such as a computer readable medium havingprogram instructions recorded thereon for practicing the methods.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages of the embodiments will become apparentfrom the following detailed description, taken in combination with theappended drawings, in which:

FIG. 1 is a graphical representation illustrating the geometry forconstructing a three-dimensional perspective viewing frustum, relativeto an x, y, z coordinate system, in accordance with elastic presentationspace graphics technology;

FIG. 2 is a graphical representation illustrating the geometry of apresentation in accordance with elastic presentation space graphicstechnology;

FIG. 3 is a block diagram illustrating a data processing system adaptedfor implementing an embodiment;

FIG. 4 is a partial screen capture illustrating a GUI having lenscontrol elements for user interaction with detail-in-context datapresentations in accordance with an embodiment;

FIG. 5 is a screen capture illustrating a presentation having a foldedlens and GUI in which hand icons are used to indicate locations on adisplay surface where a user may touch the display surface to adjust thefolding of the lens in accordance with an embodiment;

FIG. 6 is a screen capture illustrating a presentation having a twistedor rotated lens and GUI in which hand icons are used to indicatelocations on a display surface where a user may touch the displaysurface to adjust twist or rotation of the lens in accordance with anembodiment;

FIG. 7 is a screen capture illustrating a presentation of a twisted orrotated lens and GUI in which a single hand icon having splayed fingersis used to indicate the locations on the display surface where a usermay touch the display surface to adjust twist or rotation of the lens inaccordance with an embodiment;

FIG. 8 is a screen capture illustrating a presentation of an object atan initial location prior to a magnified drag operation in which handicons are used to indicate the locations of a user's fingers on a touchsensitive display surface in accordance with an embodiment;

FIG. 9 is a screen capture illustrating a presentation of the object ofFIG. 8 at a final location after the magnified draft operation isperformed in which hand icons are used to indicate the locations of auser's fingers on the touch sensitive display surface in accordance withan embodiment;

FIG. 10 is a screen capture illustrating a presentation in which firstand second lens have been applied to an original image in accordancewith an embodiment;

FIG. 11 is a screen capture illustrating a presentation in which lensfolding has been applied to provide off-screen awareness of selectedobjects of interest in FIG. 10 in accordance with an embodiment; and,

FIG. 12 is a flow chart illustrating operations of software moduleswithin the memory of a data processing system for generating apresentation of a region-of-interest in an original image for display ona display surface, in accordance with an embodiment.

It will be noted that throughout the appended drawings, like featuresare identified by like reference numerals.

DETAILED DESCRIPTION

In the following description, details are set forth to provide anunderstanding. In some instances, certain software, circuits, structuresand methods have not been described or shown in detail in order not toobscure the techniques described herein. The term “data processingsystem” is used herein to refer to any machine for processing data,including the computer systems and network arrangements describedherein. The present techniques may be implemented in any computerprogramming language provided that the operating system of the dataprocessing system provides the facilities that may support therequirements of the present techniques. Any limitations presented wouldbe a result of a particular type of operating system or computerprogramming language and would not be a limitation of the presenttechniques.

The “screen real estate problem” generally arises whenever large amountsof information are to be displayed on a display screen of limited size.Known tools to address this problem include panning and zooming. Whilethese tools are suitable for a large number of visual displayapplications, they become less effective where sections of the visualinformation are spatially related, such as in layered maps andthree-dimensional representations, for example. In this type ofinformation display, panning and zooming are not as effective as much ofthe context of the panned or zoomed display may be hidden.

A recent solution to this problem is the application of“detail-in-context” presentation techniques. Detail-in-context is themagnification of a particular region-of-interest (the “focal region” or“detail”) in a data presentation while preserving visibility of thesurrounding information (the “context”). This technique hasapplicability to the display of large surface area media (e.g. digitalmaps) on computer screens of variable size including graphicsworkstations, laptop computers, personal digital assistants (“PDAs”),and cell phones.

In the detail-in-context discourse, differentiation is often madebetween the terms “representation” and “presentation”. A representationis a formal system, or mapping, for specifying raw information or datathat is stored in a computer or data processing system. For example, adigital map of a city is a representation of raw data including streetnames and the relative geographic location of streets and utilities.Such a representation may be displayed visually on a computer screen orprinted on paper. On the other hand, a presentation is a spatialorganization of a given representation that is appropriate for the taskat hand. Thus, a presentation of a representation organizes such thingsas the point of view and the relative emphasis of different parts orregions of the representation. For example, a digital map of a city maybe presented with a region magnified to reveal street names.

In general, a detail-in-context presentation may be considered as adistorted view (or distortion) of a portion of the originalrepresentation or image where the distortion is the result of theapplication of a “lens” like distortion function to the originalrepresentation. A detailed review of various detail-in-contextpresentation techniques such as “Elastic Presentation Space” (“EPS”) (or“Pliable Display Technology” (“PDT”)) may be found in a publication byMarianne S. T. Carpendale, entitled “A Framework for ElasticPresentation Space” (Carpendale, Marianne S. T., A Framework for ElasticPresentation Space (Burnaby, British Columbia: Simon Fraser University,1999)), and incorporated herein by reference.

In general, detail-in-context data presentations are characterized bymagnification of areas of an image where detail is desired, incombination with compression of a restricted range of areas of theremaining information (i.e. the context), the result typically givingthe appearance of a lens having been applied to the display surface.Using the techniques described by Carpendale, points in a representationare displaced in three dimensions and a perspective projection is usedto display the points on a two-dimensional presentation display. Thus,when a lens is applied to a two-dimensional continuous surfacerepresentation, for example, the resulting presentation appears to bethree-dimensional. In other words, the lens transformation appears tohave stretched the continuous surface in a third dimension. In EPSgraphics technology, a two-dimensional visual representation is placedonto a surface; this surface is placed in three-dimensional space; thesurface, containing the representation, is viewed through perspectiveprojection; and the surface is manipulated to effect the reorganizationof image details. The presentation transformation is separated into twosteps: surface manipulation or distortion and perspective projection.

FIG. 1 is a graphical representation illustrating the geometry 100 forconstructing a three-dimensional (“3D”) perspective viewing frustum 220,relative to an x, y, z coordinate system, in accordance with elasticpresentation space (EPS) graphics technology. In EPS technology,detail-in-context views of two-dimensional (“2D”) visual representationsare created with sight-line aligned distortions of a 2D informationpresentation surface within a 3D perspective viewing frustum 220. InEPS, magnification of regions of interest and the accompanyingcompression of the contextual region to accommodate this change in scaleare produced by the movement of regions of the surface towards theviewpoint (“VP”) 240 located at the apex of the pyramidal shape 220containing the frustum. The process of projecting these transformedlayouts via a perspective projection results in a new 2D layout whichincludes the zoomed and compressed regions. The use of the thirddimension and perspective distortion to provide magnification in EPSprovides a meaningful metaphor for the process of distorting theinformation presentation surface. The 3D manipulation of the informationpresentation surface in such a system is an intermediate step in theprocess of creating a new 2D layout of the information.

FIG. 2 is a graphical representation illustrating the geometry 200 of apresentation in accordance with EPS graphics technology. EPS graphicstechnology employs viewer-aligned perspective projections to producedetail-in-context presentations in a reference view plane 201 which maybe viewed on a display. Undistorted 2D data points are located in abasal plane 210 of a 3D perspective viewing volume or frustum 220 whichis defined by extreme rays 221 and 222 and the basal plane 210. The VP240 is generally located above the centre point of the basal plane 210and reference view plane (“RVP”) 201. Points in the basal plane 210 aredisplaced upward onto a distorted surface 230 which is defined by ageneral 3D distortion function (i.e. a detail-in-context distortionbasis function). The direction of the perspective projectioncorresponding to the distorted surface 230 is indicated by the lineFPo-FP 231 drawn from a point FPo 232 in the basal plane 210 through thepoint FP 233 which corresponds to the focus or focal region or focalpoint of the distorted surface 230. Typically, the perspectiveprojection has a direction 231 that is viewer-aligned (i.e., the pointsFPo 232, FP 233, and VP 240 are collinear).

EPS is applicable to multidimensional data and is well suited toimplementation on a computer for dynamic detail-in-context display on anelectronic display surface such as a monitor. In the case of twodimensional data, EPS is typically characterized by magnification ofareas of an image where detail is desired 233, in combination withcompression of a restricted range of areas of the remaining information(i.e. the context) 234, the end result typically giving the appearanceof a lens 230 having been applied to the display surface. The areas ofthe lens 230 where compression occurs may be referred to as the“shoulder” 234 of the lens 230. The area of the representationtransformed by the lens may be referred to as the “lensed area”. Thelensed area thus includes the focal region and the shoulder. Toreiterate, the source image or representation to be viewed is located inthe basal plane 210. Magnification 233 and compression 234 are achievedthrough elevating elements of the source image relative to the basalplane 210, and then projecting the resultant distorted surface onto thereference view plane 201. EPS performs detail-in-context presentation ofn-dimensional data through the use of a procedure wherein the data ismapped into a region in an (n+1) dimensional space, manipulated throughperspective projections in the (n+1) dimensional space, and then finallytransformed back into n-dimensional space for presentation. EPS hasnumerous advantages over conventional zoom, pan, and scrolltechnologies, including the capability of preserving the visibility ofinformation outside 234 the local region of interest 233.

For example, and referring to FIGS. 1 and 2, in two dimensions, EPS canbe implemented through the projection of an image onto a reference plane201 in the following manner. The source image or representation islocated on a basal plane 210, and those regions of interest 233 of theimage for which magnification is desired are elevated so as to move themcloser to a reference plane situated between the reference viewpoint 240and the reference view plane 201. Magnification of the focal region 233closest to the RVP 201 varies inversely with distance from the RVP 201.As shown in FIGS. 1 and 2, compression of regions 234 outside the focalregion 233 is a function of both distance from the RVP 201, and thegradient of the function describing the vertical distance from the RVP201 with respect to horizontal distance from the focal region 233. Theresultant combination of magnification 233 and compression 234 of theimage as seen from the reference viewpoint 240 results in a lens-likeeffect similar to that of a magnifying glass applied to the image.Hence, the various functions used to vary the magnification andcompression of the source image via vertical displacement from the basalplane 210 are described as lenses, lens types, or lens functions. Lensfunctions that describe basic lens types with point and circular focalregions, as well as certain more complex lenses and advancedcapabilities such as folding, have previously been described byCarpendale.

FIG. 3 is a block diagram of a data processing system 300 adapted toimplement an embodiment. The data processing system 300 is suitable forgenerating, displaying, and adjusting detail-in-context lenspresentations in conjunction with a detail-in-context graphical userinterface (GUI) 400, as described below. The data processing system 300includes an input device 310, a central processing unit (“CPU”) 320,memory 330, a display 340, and an interface device 350. The input device310 may include a keyboard, a mouse, a trackball, a touch sensitivesurface or screen, a position tracking device, an eye tracking device,or a similar device. The CPU 320 may include dedicated coprocessors andmemory devices. The memory 330 may include RAM, ROM, databases, or diskdevices. The display 340 may include a computer screen, terminal device,a touch sensitive display surface or screen, or a hardcopy producingoutput device such as a printer or plotter. And, the interface device350 may include an interface to a network (not shown) such as theInternet. Thus, the data processing system 300 may be linked to otherdata processing systems (not shown) by a network (not shown). The dataprocessing system 300 has stored therein data representing sequences ofinstructions which when executed cause the method described herein to beperformed. Of course, the data processing system 300 may containadditional software and hardware.

Thus, the data processing system 300 includes computer executableprogrammed instructions for directing the system 300 to implement theembodiments. The programmed instructions may be embodied in one or moresoftware modules 331 resident in the memory 330 of the data processingsystem 300. Alternatively, the programmed instructions may be embodiedon a computer readable medium (such as a CD disk or floppy disk) whichmay be used for transporting the programmed instructions to the memory330 of the data processing system 300. Alternatively, the programmedinstructions may be embedded in a computer-readable, signal-bearingmedium that is uploaded to a network by a vendor or supplier of theprogrammed instructions, and this signal-bearing medium may bedownloaded through an interface to the data processing system 300 fromthe network by end users or potential buyers.

As mentioned, detail-in-context presentations of data using techniquessuch as pliable surfaces, as described by Carpendale, are useful inpresenting large amounts of information on limited-size displaysurfaces. Detail-in-context views allow magnification of a particularregion-of-interest (the “focal region”) 233 in a data presentation whilepreserving visibility of the surrounding information 210. In thefollowing, a GUI 400 is described having lens control elements that canbe implemented in software and applied to the control ofdetail-in-context data presentations. The software can be loaded intoand run by the data processing system 300 of FIG. 3.

FIG. 4 is a partial screen capture illustrating a GUI 400 having lenscontrol elements for user interaction with detail-in-context datapresentations in accordance with an embodiment. Detail-in-context datapresentations are characterized by magnification of areas of an imagewhere detail is desired, in combination with compression of a restrictedrange of areas of the remaining information (i.e. the context), the endresult typically giving the appearance of a lens having been applied tothe display screen surface. This lens 410 includes a “focal region” 420having high magnification, a surrounding “shoulder region” 430 whereinformation is typically visibly compressed, and a “base” 412surrounding the shoulder region 430 and defining the extent of the lens410. In FIG. 4, the lens 410 is shown with a circular shaped base 412(or outline) and with a focal region 420 lying near the center of thelens 410. However, the lens 410 and focal region 420 may have anydesired shape. As mentioned above, the base of the lens 412 may becoextensive with the focal region 420.

In general, the GUI 400 has lens control elements that, in combination,provide for the interactive control of the lens 410. The effectivecontrol of the characteristics of the lens 410 by a user (i.e., dynamicinteraction with a detail-in-context lens) is advantageous. At any giventime, one or more of these lens control elements may be made visible tothe user on the display surface 340 by appearing as overlay icons on thelens 410. Interaction with each element is performed via the motion ofan input or pointing device 310 (e.g., a mouse) with the motionresulting in an appropriate change in the corresponding lenscharacteristic. As will be described, selection of which lens controlelement is actively controlled by the motion of the pointing device 310at any given time is determined by the proximity of the iconrepresenting the pointing device 310 (e.g. cursor) on the displaysurface 340 to the appropriate component of the lens 410. For example,“dragging” of the pointing device at the periphery of the boundingrectangle of the lens base 412 causes a corresponding change in the sizeof the lens 410 (i.e. “resizing”). Thus, the GUI 400 provides the userwith a visual representation of which lens control element is beingadjusted through the display of one or more corresponding icons.

For ease of understanding, the following discussion will be in thecontext of using a two-dimensional pointing device 310 that is a mouse,but it will be understood that the techniques may be practiced withother 2D or 3D (or even greater numbers of dimensions) input devicesincluding a trackball, a keyboard, a position tracking device, an eyetracking device, an input from a navigation device, etc.

A mouse 310 controls the position of a cursor icon 401 that is displayedon the display screen 340. The cursor 401 is moved by moving the mouse310 over a flat surface, such as the top of a desk, in the desireddirection of movement of the cursor 401. Thus, the two-dimensionalmovement of the mouse 310 on the flat surface translates into acorresponding two-dimensional movement of the cursor 401 on the displayscreen 340.

A mouse 310 typically has one or more finger actuated control buttons(i.e. mouse buttons). While the mouse buttons can be used for differentfunctions such as selecting a menu option pointed at by the cursor 401,the disclosed techniques may use a single mouse button to “select” alens 410 and to trace the movement of the cursor 401 along a desiredpath. Specifically, to select a lens 410, the cursor 401 is firstlocated within the extent of the lens 410. In other words, the cursor401 is “pointed” at the lens 410. Next, the mouse button is depressedand released. That is, the mouse button is “clicked”. Selection is thusa point and click operation. To trace the movement of the cursor 401,the cursor 401 is located at the desired starting location, the mousebutton is depressed to signal the computer 320 to activate a lenscontrol element, and the mouse 310 is moved while maintaining the buttondepressed. After the desired path has been traced, the mouse button isreleased. This procedure is often referred to as “clicking” and“dragging” (i.e. a click and drag operation). It will be understood thata predetermined key on a keyboard 310 could also be used to activate amouse click or drag. In the following, the term “clicking” will refer tothe depression of a mouse button indicating a selection by the user andthe term “dragging” will refer to the subsequent motion of the mouse 310and cursor 401 without the release of the mouse button.

The GUI 400 may include the following lens control elements: move,pickup, resize base, resize focus, fold, magnify, zoom, and scoop. Eachof these lens control elements has at least one lens control icon oralternate cursor icon associated with it. In general, when a lens 410 isselected by a user through a point and click operation, the followinglens control icons may be displayed over the lens 410: pickup icon 450,base outline icon 412, base bounding rectangle icon 411, focal regionbounding rectangle icon 421, handle icons 481, 482, 491, 492 magnifyslide bar icon 440, zoom icon 495, and scoop slide bar icon 550 (seeFIG. 5). Typically, these icons are displayed simultaneously afterselection of the lens 410. In addition, when the cursor 401 is locatedwithin the extent of a selected lens 410, an alternate cursor icon 460,470, 480, 490, 495 may be displayed over the lens 410 to replace thecursor 401 or may be displayed in combination with the cursor 401. Theselens control elements, corresponding icons, and their effects on thecharacteristics of a lens 410 are described below with reference to FIG.4.

In general, when a lens 410 is selected by a point and click operation,bounding rectangle icons 411, 421 are displayed surrounding the base 412and focal region 420 of the selected lens 410 to indicate that the lens410 has been selected. With respect to the bounding rectangles 411, 421one might view them as glass windows enclosing the lens base 412 andfocal region 420, respectively. The bounding rectangles 411, 421 includehandle icons 481, 482, 491, 492 allowing for direct manipulation of theenclosed base 412 and focal region 420 as will be explained below. Thus,the bounding rectangles 411, 421 not only inform the user that the lens410 has been selected, but also provide the user with indications as towhat manipulation operations might be possible for the selected lens 410though use of the displayed handles 481, 482, 491, 492. Note that it iswell within the scope of the present techniques to provide a boundingregion having a shape other than generally rectangular. Such a boundingregion could be of any of a great number of shapes including oblong,oval, ovoid, conical, cubic, cylindrical, polyhedral, spherical, etc.

Moreover, the cursor 401 provides a visual cue indicating the nature ofan available lens control element. As such, the cursor 401 willgenerally change in form by simply pointing to a different lens controlicon 450, 412, 411, 421, 481, 482, 491, 492, 440, 550. For example, whenresizing the base 412 of a lens 410 using a corner handle 491, thecursor 401 will change form to a resize icon 490 once it is pointed at(i.e. positioned over) the corner handle 491. The cursor 401 will remainin the foam of the resize icon 490 until the cursor 401 has been movedaway from the corner handle 491.

Lateral movement of a lens 410 is provided by the move lens controlelement of the GUI 400. This functionality is accomplished by the userfirst selecting the lens 410 through a point and click operation. Then,the user points to a point within the lens 410 that is other than apoint lying on a lens control icon 450, 412, 411, 421, 481, 482, 491,492, 440, 550. When the cursor 401 is so located, a move icon 460 isdisplayed over the lens 410 to replace the cursor 401 or may bedisplayed in combination with the cursor 401. The move icon 460 not onlyinforms the user that the lens 410 may be moved, but also provides theuser with indications as to what movement operations are possible forthe selected lens 410. For example, the move icon 460 may includearrowheads indicating up, down, left, and right motion. Next, the lens410 is moved by a click and drag operation in which the user clicks anddrags the lens 410 to the desired position on the screen 340 and thenreleases the mouse button 310. The lens 410 is locked in its newposition until a further pickup and move operation is performed.

Lateral movement of a lens 410 is also provided by the pickup lenscontrol element of the GUI. This functionality is accomplished by theuser first selecting the lens 410 through a point and click operation.As mentioned above, when the lens 410 is selected a pickup icon 450 isdisplayed over the lens 410 near the centre of the lens 410. Typically,the pickup icon 450 will be a crosshairs. In addition, a base outline412 is displayed over the lens 410 representing the base 412 of the lens410. The crosshairs 450 and lens outline 412 not only inform the userthat the lens has been selected, but also provides the user with anindication as to the pickup operation that is possible for the selectedlens 410. Next, the user points at the crosshairs 450 with the cursor401. Then, the lens outline 412 is moved by a click and drag operationin which the user clicks and drags the crosshairs 450 to the desiredposition on the screen 340 and then releases the mouse button 310. Thefull lens 410 is then moved to the new position and is locked thereuntil a further pickup operation is performed. In contrast to the moveoperation described above, with the pickup operation, it is the outline412 of the lens 410 that the user repositions rather than the full lens410.

Resizing of the base 412 (or outline) of a lens 410 is provided by theresize base lens control element of the GUI. After the lens 410 isselected, a bounding rectangle icon 411 is displayed surrounding thebase 412. For a rectangular shaped base 412, the bounding rectangle icon411 may be coextensive with the perimeter of the base 412. The boundingrectangle 411 includes handles 491, 492. These handles 491, 492 can beused to stretch the base 412 taller or shorter, wider or narrower, orproportionally larger or smaller. The corner handles 491 will keep theproportions the same while changing the size. The middle handles 492(see FIG. 5) will make the base 412 taller or shorter, wider ornarrower. Resizing the base 412 by the corner handles 491 will keep thebase 412 in proportion. Resizing the base 412 by the middle handles 492will change the proportions of the base 412. That is, the middle handles492 change the aspect ratio of the base 412 (i.e. the ratio between theheight and the width of the bounding rectangle 411 of the base 412).When a user points at a handle 491, 492 with the cursor 401 a resizeicon 490 may be displayed over the handle 491, 492 to replace the cursor401 or may be displayed in combination with the cursor 401. The resizeicon 490 not only informs the user that the handle 491, 492 may beselected, but also provides the user with indications as to the resizingoperations that are possible with the selected handle. For example, theresize icon 490 for a corner handle 491 may include arrows indicatingproportional resizing. The resize icon (not shown) for a middle handle492 may include arrows indicating width resizing or height resizing.After pointing at the desired handle 491, 492 the user would click anddrag the handle 491, 492 until the desired shape and size for the base412 is reached. Once the desired shape and size are reached, the userwould release the mouse button 310. The base 412 of the lens 410 is thenlocked in its new size and shape until a further base resize operationis performed.

Resizing of the focal region 420 of a lens 410 is provided by the resizefocus lens control element of the GUI. After the lens 410 is selected, abounding rectangle icon 421 is displayed surrounding the focal region420. For a rectangular shaped focal region 420, the bounding rectangleicon 421 may be coextensive with the perimeter of the focal region 420.The bounding rectangle 421 includes handles 481, 482. These handles 481,482 can be used to stretch the focal region 420 taller or shorter, wideror narrower, or proportionally larger or smaller. The corner handles 481will keep the proportions the same while changing the size. The middlehandles 482 will make the focal region 420 taller or shorter, wider ornarrower. Resizing the focal region 420 by the corner handles 481 willkeep the focal region 420 in proportion. Resizing the focal region 420by the middle handles 482 will change the proportions of the focalregion 420. That is, the middle handles 482 change the aspect ratio ofthe focal region 420 (i.e. the ratio between the height and the width ofthe bounding rectangle 421 of the focal region 420). When a user pointsat a handle 481, 482 with the cursor 401 a resize icon 480 may bedisplayed over the handle 481, 482 to replace the cursor 401 or may bedisplayed in combination with the cursor 401. The resize icon 480 notonly informs the user that a handle 481, 482 may be selected, but alsoprovides the user with indications as to the resizing operations thatare possible with the selected handle. For example, the resize icon 480for a corner handle 481 may include arrows indicating proportionalresizing. The resize icon 480 for a middle handle 482 may include arrowsindicating width resizing or height resizing. After pointing at thedesired handle 481, 482, the user would click and drag the handle 481,482 until the desired shape and size for the focal region 420 isreached. Once the desired shape and size are reached, the user wouldrelease the mouse button 310. The focal region 420 is then locked in itsnew size and shape until a further focus resize operation is performed.

Folding of the focal region 420 of a lens 410 is provided by the foldcontrol element of the GUI. In general, control of the degree anddirection of folding (i.e. skewing of the viewer aligned vector 231 asdescribed by Carpendale) is accomplished by a click and drag operationon a point 471, other than a handle 481, 482, on the bounding rectangle421 surrounding the focal region 420. The direction of folding isdetermined by the direction in which the point 471 is dragged. Thedegree of folding is determined by the magnitude of the translation ofthe cursor 401 during the drag. In general, the direction and degree offolding corresponds to the relative displacement of the focus 420 withrespect to the lens base 410. In other words, and referring to FIG. 2,the direction and degree of folding corresponds to the displacement ofthe point FP 233 relative to the point FPo 232, where the vector joiningthe points FPo 232 and FP 233 defines the viewer aligned vector 231. Inparticular, after the lens 410 is selected, a bounding rectangle icon421 is displayed surrounding the focal region 420. The boundingrectangle 421 includes handles 481, 482. When a user points at a point471, other than a handle 481, 482, on the bounding rectangle 421surrounding the focal region 420 with the cursor 401, a fold icon 470may be displayed over the point 471 to replace the cursor 401 or may bedisplayed in combination with the cursor 401. The fold icon 470 not onlyinforms the user that a point 471 on the bounding rectangle 421 may beselected, but also provides the user with indications as to what foldoperations are possible. For example, the fold icon 470 may includearrowheads indicating up, down, left, and right motion. By choosing apoint 471, other than a handle 481, 482, on the bounding rectangle 421 auser may control the degree and direction of folding. To control thedirection of folding, the user would click on the point 471 and drag inthe desired direction of folding. To control the degree of folding, theuser would drag to a greater or lesser degree in the desired directionof folding. Once the desired direction and degree of folding is reached,the user would release the mouse button 310. The lens 410 is then lockedwith the selected fold until a further fold operation is performed.

Magnification of the lens 410 is provided by the magnify lens controlelement of the GUI. After the lens 410 is selected, the magnify controlis presented to the user as a slide bar icon 440 near or adjacent to thelens 410 and typically to one side of the lens 410. Sliding the bar 441of the slide bar 440 results in a proportional change in themagnification of the lens 410. The slide bar 440 not only informs theuser that magnification of the lens 410 may be selected, but alsoprovides the user with an indication as to what level of magnificationis possible. The slide bar 440 includes a bar 441 that may be slid upand down, or left and right, to adjust and indicate the level ofmagnification. To control the level of magnification, the user wouldclick on the bar 441 of the slide bar 440 and drag in the direction ofdesired magnification level. Once the desired level of magnification isreached, the user would release the mouse button 310. The lens 410 isthen locked with the selected magnification until a furthermagnification operation is performed. In general, the focal region 420is an area of the lens 410 having constant magnification (i.e. if thefocal region is a plane). Again referring to FIGS. 1 and 2,magnification of the focal region 420, 233 varies inversely with thedistance from the focal region 420, 233 to the reference view plane(RVP) 201. Magnification of areas lying in the shoulder region 430 ofthe lens 410 also varies inversely with their distance from the RVP 201.Thus, magnification of areas lying in the shoulder region 430 will rangefrom unity at the base 412 to the level of magnification of the focalregion 420.

Zoom functionality is provided by the zoom lens control element of theGUI. Referring to FIG. 2, the zoom lens control element, for example,allows a user to quickly navigate to a region of interest 233 within acontinuous view of a larger presentation 210 and then zoom in to thatregion of interest 233 for detailed viewing or editing. Referring toFIG. 4, the combined presentation area covered by the focal region 420and shoulder region 430 and surrounded by the base 412 may be referredto as the “extent of the lens”. Similarly, the presentation area coveredby the focal region 420 may be referred to as the “extent of the focalregion”. The extent of the lens may be indicated to a user by a basebounding rectangle 411 when the lens 410 is selected. The extent of thelens may also be indicated by an arbitrarily shaped figure that boundsor is coincident with the perimeter of the base 412. Similarly, theextent of the focal region may be indicated by a second boundingrectangle 421 or arbitrarily shaped figure. The zoom lens controlelement allows a user to: (a) “zoom in” to the extent of the focalregion such that the extent of the focal region fills the display screen340 (i.e. “zoom to focal region extent”); (b) “zoom in” to the extent ofthe lens such that the extent of the lens fills the display screen 340(i.e. “zoom to lens extent”); or, (c) “zoom in” to the area lyingoutside of the extent of the focal region such that the area without thefocal region is magnified to the same level as the extent of the focalregion (i.e. “zoom to scale”).

In particular, after the lens 410 is selected, a bounding rectangle icon411 is displayed surrounding the base 412 and a bounding rectangle icon421 is displayed surrounding the focal region 420. Zoom functionality isaccomplished by the user first selecting the zoom icon 495 through apoint and click operation When a user selects zoom functionality, a zoomcursor icon 496 may be displayed to replace the cursor 401 or may bedisplayed in combination with the cursor 401. The zoom cursor icon 496provides the user with indications as to what zoom operations arepossible. For example, the zoom cursor icon 496 may include a magnifyingglass. By choosing a point within the extent of the focal region, withinthe extent of the lens, or without the extent of the lens, the user maycontrol the zoom function. To zoom in to the extent of the focal regionsuch that the extent of the focal region fills the display screen 340(i.e. “zoom to focal region extent”), the user would point and clickwithin the extent of the focal region. To zoom in to the extent of thelens such that the extent of the lens fills the display screen 340 (i.e.“zoom to lens extent”), the user would point and click within the extentof the lens. Or, to zoom in to the presentation area without the extentof the focal region, such that the area without the extent of the focalregion is magnified to the same level as the extent of the focal region(i.e. “zoom to scale”), the user would point and click without theextent of the lens. After the point and click operation is complete, thepresentation is locked with the selected zoom until a further zoomoperation is performed.

Alternatively, rather than choosing a point within the extent of thefocal region, within the extent of the lens, or without the extent ofthe lens to select the zoom function, a zoom function menu with multipleitems (not shown) or multiple zoom function icons (not shown) may beused for zoom function selection. The zoom function menu may bepresented as a pull-down menu. The zoom function icons may be presentedin a toolbar or adjacent to the lens 410 when the lens is selected.Individual zoom function menu items or zoom function icons may beprovided for each of the “zoom to focal region extent”, “zoom to lensextent”, and “zoom to scale” functions described above. In thisalternative, after the lens 410 is selected, a bounding rectangle icon411 may be displayed surrounding the base 412 and a bounding rectangleicon 421 may be displayed surrounding the focal region 420. Zoomfunctionality is accomplished by the user selecting a zoom function fromthe zoom function menu or via the zoom function icons using a point andclick operation. In this way, a zoom function may be selected withoutconsidering the position of the cursor 401 within the lens 410.

The concavity or “scoop” of the shoulder region 430 of the lens 410 isprovided by the scoop lens control element of the GUI. After the lens410 is selected, the scoop control is presented to the user as a slidebar icon 550 (see FIG. 5) near or adjacent to the lens 410 and typicallybelow the lens 410. Sliding the bar 551 (see FIG. 5) of the slide bar550 results in a proportional change in the concavity or scoop of theshoulder region 430 of the lens 410. The slide bar 550 not only informsthe user that the shape of the shoulder region 430 of the lens 410 maybe selected, but also provides the user with an indication as to whatdegree of shaping is possible. The slide bar 550 includes a bar 551 thatmay be slid left and right, or up and down, to adjust and indicate thedegree of scooping. To control the degree of scooping, the user wouldclick on the bar 551 of the slide bar 550 and drag in the direction ofdesired scooping degree. Once the desired degree of scooping is reached,the user would release the mouse button 310. The lens 410 is then lockedwith the selected scoop until a further scooping operation is performed.

Advantageously, a user may choose to hide one or more lens control icons450, 412, 411, 421, 481, 482, 491, 492, 440, 495, 550 shown in FIGS. 4and 5 from view so as not to impede the user's view of the image withinthe lens 410. This may be helpful, for example, during an editing ormove operation. A user may select this option through means such as amenu, toolbar, or lens property dialog box.

In addition, the GUI 400 maintains a record of control elementoperations such that the user may restore pre-operation presentations.This record of operations may be accessed by or presented to the userthrough “Undo” and “Redo” icons 497, 498, through a pull-down operationhistory menu (not shown), or through a toolbar.

Thus, detail-in-context data viewing techniques allow a user to viewmultiple levels of detail or resolution on one display 340. Theappearance of the data display or presentation is that of one or morevirtual lenses showing detail 233 within the context of a larger areaview 210. Using multiple lenses in detail-in-context data presentationsmay be used to compare two regions of interest at the same time. Foldingenhances this comparison by allowing the user to pull the regions ofinterest closer together. Moreover, using detail-in-context technology,an area of interest can be magnified to pixel level resolution, or toany level of detail available from the source information, for in-depthreview. The digital images may include graphic images, maps,photographic images, or text documents, and the source information maybe in raster, vector, or text form.

For example, in order to view a selected object or area in detail, auser can define a lens 410 over the object using the GUI 400. The lens410 may be introduced to the original image to form the a presentationthrough the use of a pull-down menu selection, tool bar icon, etc. Usinglens control elements for the GUI 400, such as move, pickup, resizebase, resize focus, fold, magnify, zoom, and scoop, as described above,the user adjusts the lens 410 for detailed viewing of the object orarea. Using the magnify lens control element, for example, the user maymagnify the focal region 420 of the lens 410 to pixel quality resolutionrevealing detailed information pertaining to the selected object orarea. That is, a base image (i.e., the image outside the extent of thelens) is displayed at a low resolution while a lens image (i.e., theimage within the extent of the lens) is displayed at a resolution basedon a user selected magnification 440, 441.

In operation, the data processing system 300 employs EPS techniques withan input device 310 and GUI 400 for selecting objects or areas fordetailed display to a user on a display screen 340. Data representing anoriginal image or representation is received by the CPU 320 of the dataprocessing system 300. Using EPS techniques, the CPU 320 processes thedata in accordance with instructions received from the user via an inputdevice 310 and GUI 400 to produce a detail-in-context presentation. Thepresentation is presented to the user on a display screen 340. It willbe understood that the CPU 320 may apply a transformation to theshoulder region 430 surrounding the region-of-interest 420 to affectblending or folding in accordance with EPS techniques. For example, thetransformation may map the region-of-interest 420 and/or shoulder region430 to a predefined lens surface, defined by a transformation ordistortion function and having a variety of shapes, using EPStechniques. Or, the lens 410 may be simply coextensive with theregion-of-interest 420.

The lens control elements of the GUI 400 are adjusted by the user via aninput device 310 to control the characteristics of the lens 410 in thedetail-in-context presentation. Using an input device 310 such as amouse, a user adjusts parameters of the lens 410 using icons and scrollbars of the GUI 400 that are displayed over the lens 410 on the displayscreen 340. The user may also adjust parameters of the image of the fullscene. Signals representing input device 310 movements and selectionsare transmitted to the CPU 320 of the data processing system 300 wherethey are translated into instructions for lens control.

Moreover, the lens 410 may be added to the presentation before or afterthe object or area is selected. That is, the user may first add a lens410 to a presentation or the user may move a pre-existing lens intoplace over the selected object or area. The lens 410 may be introducedto the original image to form the presentation through the use of apull-down menu selection, tool bar icon, etc.

Advantageously, by using a detail-in-context lens 410 to select anobject or area for detailed information gathering, a user can view alarge area (i.e., outside the extent of the lens 410) while focusing inon a smaller area (or within the focal region 420 of the lens 410)surrounding the selected object. This makes it possible for a user toaccurately gather detailed information without losing visibility orcontext of the portion of the original image surrounding the selectedobject.

Now, a touch sensitive direct interaction multi-input display surface340 (often implemented as tabletops, wall-screens, or other formats)allows a computer system 300 to sense touches on the surface 340 by avariety of users simultaneously. In effect, the display surface 340combines the function of a traditional display screen 340 and one ormore input devices 310. Several users can simultaneously touch theirfingers or hands to the surface 340 to manipulate data presentedthereon. An individual user can also simultaneously use both hands orseveral fingers in order to perform multi-point interaction with thecomputer system 300. In the following, methods are described in whichtouch sensitive surfaces or display surfaces 340 can be used inconjunction with detail-in-context lenses 410 to generate and adjustdetail-in-context presentations. Also described are methods related topresentation systems that don't necessarily involve touch sensitivesurfaces or display surfaces 340. A user may enable input through thetouch sensitive surface or display surface 340 by making an appropriateselection from a menu or toolbar.

FIG. 5 is a screen capture illustrating a presentation 500 having afolded lens 410 and GUI 400 in which hand icons 501, 502 are used toindicate locations 420, 430 on a display surface 340 where a user maytouch the display surface 340 to adjust the folding of the lens 410 inaccordance with an embodiment. In this embodiment, the user may adjustthe folding of the lens 410 using one or both hands 501, 502. Incontrolling the folding of a lens 410 as described above, the action ofdragging the focal region 420 of the lens 410 outside of the boundingrectangle 411 of the lens 410, performed using relatively small-sizedcontrol icons, can be problematic in cases where input resolution is notgreat. According to one embodiment, a method of enabling folding isprovided that employs a direct interaction approach in which the lens410 may be manipulated as if it were made from a clay-like substance.This embodiment allows for manipulation of the lens 410 via directtouching of the display surface on which it is presented with one orboth of the user's hands.

In this embodiment, if a user touches the lens 410 presented on thedisplay surface 340 with a single hand (or finger) and then drags his orher hand (or finger) across the display surface 340, the lens 410 willbe repositioned as a single unit. That is, both the focal region 420 andshoulder region 430 will retain their relative positions. Thisembodiment thus includes a method of lateral repositioning of the lens410. Now, in order to fold the lens 410 according to this embodiment,the user touches the lens 410 in the base or shoulder region 430 with afirst hand (or finger) 501 and in the focal region 420 with a secondhand (or finger) 502. When the user draws his or her hands apart, whilemaintaining contact with the display surface 340, the presentation ofthe lens 410 is stretched, as if it were clay. The focal region 420 canbe pulled outside of the bounds 411, 412 of the lens 410 to create afolded lens 410 as shown in FIG. 5 by the user repositioning his or hersecond hand 502. In addition, if the user moves his or her first hand501, the base 430 of the lens 410 can be repositioned. Thus, the focalregion 420 and base 430 can be manipulated independently orsimultaneously to create a folded lens 410. Clay is used as a metaphorhere, rather than rubber, because with rubber the lens would “snap” backto its original shape once released rather than retaining its stretched(i.e., folded) form as is the case with this embodiment.

Now, multiple users working with a touch-sensitive surface or displaysurface may be located on different sides of the surface (e.g., theusers may be sitting around a tabletop display surface). With differentperspectives, these users will have different preferences with respectto the orientation of objects presented on the display surface.Consequently, there is a need for rotation (or twisting) of visualobjects presented on the display surface to facilitate different userorientation preferences. According to one embodiment, detail-in-contextlenses satisfy this need by incorporating a rotational component intheir displacement or distortion functions. In particular, according tothis embodiment, the more a point is magnified by the lens (i.e.,geometrically closer to the center of the lens), the more it is rotated(or twisted) about the central axis of the lens.

FIG. 6 is a screen capture illustrating a presentation 600 having atwisted or rotated lens 410 and GUI 400 in which hand icons 501, 502 areused to indicate locations 521, 522 on a display surface 340 where auser may touch the display surface 340 to adjust twist or rotation ofthe lens 410 in accordance with an embodiment. FIG. 7 is a screencapture illustrating a presentation 700 of a twisted or rotated lens 410and GUI 400 in which a single hand icon 710 having splayed fingers 701,702 is used to indicate the locations 521, 522 on the display surface340 where a user may touch the display surface 340 to adjust twist orrotation of the lens 410 in accordance with an embodiment. Thus, FIGS. 6and 7 illustrate adjustment of rotation/twist using two hands 501, 502and a single hand 710, respectively. In FIGS. 6 and 7, the hands 501,502 or fingers 701, 702 on a hand 710 are moved in a clockwise directionto generate a corresponding clockwise rotation of the lens 410.

Referring to FIG. 7, adjustment of the rotation in a lens 410 on atouch-sensitive display surface 340 capable of sensing multiple touchpoints is accomplished by sensing two fingertips 701, 702 from a user'shand 710 splayed and pressed against the presentation of the lens 410 toindicate two respective locations 521, 522 within the focal region 420of the lens 410. When the fingers 701, 702 are rotated around theircenter, as a user would naturally do if the user were, for example,turning a piece of paper on a table, the rotation of the lens 410 ischanged correspondingly. Referring to FIG. 6, adjustment of the rotationin the lens 410 can also be performed using a single finger from each oftwo hands 501, 502. The user places a finger from each hand 501, 502,each at a respective location 521, 522 in the focal region 420 of thelens 410 (e.g., near the perimeter 421 of the focal region 420), andthen moves both fingers either clockwise or counter clockwise, in orderto initiate a rotation in the lens 410.

Another aspect of the “screen real estate problem” is that of accuratelyselecting points in large representations or images. It is oftennecessary, for example in a measurement task, to simultaneously andaccurately specify the location of two points in a representationpresented on a display screen or surface 340. The two points may bespaced very far apart from one another, relative to the desired level ofaccuracy. According to one embodiment, as described below, a method isprovided for specifying the location of such points for a computersystem 300 equipped with a keyboard, mouse, and display screen.According to another embodiment, a method is provided for specifying thelocation of the points for a computer system 300 equipped with a touchsensitive surface or display surface 340.

With respect to the case of mouse/keyboard interaction, consider ascenario where a user has zoomed in on a region-of-interest in arepresentation where the first of two points of interest is located. Theuser selects the first point by positioning the cursor over the pointand by clicking the mouse button. The user then begins a cursor draggingoperation away from the first point toward the location of the secondpoint. Now, assuming the second point is located off the edge of thedisplay screen, the user drags the cursor to the edge of the displayscreen in the direction of the second point. When the cursor reaches theedge of the display screen, the view simultaneously zooms out and pansor scrolls in the direction of cursor movement, such that the viewablearea increases and both points remain in view near respective edges ofthe viewable area. As the panning or scrolling occurs, according to thisembodiment, two lenses may appear in the presentation, one over thefirst specified point, and one over the current cursor location. Themagnification of each lens can be automatically set such that the focalregion of each lens displays each respective point at the same scale asthe original image (i.e., the scale or zoom level of the presentationwhen the first point was selected). The user continues to pan or scrollthe view until the location of the second point of interest is visibleon the display screen. The user then positions the cursor over thesecond point, using the lens which shows the second point in its focalregion at the original image scale, and places the point.

With respect to the case of touch sensitive surface or display surfaceinteraction, this interaction operates identically to the mouse/keyboardinteraction described above with the following exceptions. First, afinger from each of a user's hands is used to specify each of the twopoints on the touch sensitive display surface. Second, either finger canbe used to scroll or pan the view to adjust the locations of the points.Thus, according to this embodiment, the two points need not be specifiedsequentially, as in the case of mouse/keyboard interaction as describedabove. Advantageously, both points can be adjusted dynamically andsimultaneously until the desired locations for the two points areselected by the user.

Another aspect of the “screen real estate problem” is that of accessingremote on-screen content from a current working location. Most solutionsfor accessing remote content from a current working location involvemoving from the current location to the remote content area. in U.S.Patent Application Publication Number 2004/0150664 by Baudisch and in arecent paper by Baudisch (i.e., Baudisch, P. et al., “Drag-and-Pop andDrag-and-Pick: Techniques for Accessing Remote Screen Content on Touch-and Pen-Operated Systems”, Proceedings of Interact 2003, Zurich,Switzerland, pp. 57-64), both of which are incorporated herein byreference, a “drag-and-pop” method for accessing remote screen contentis described. In this method a user's “activation gesture” is detected.The activation gesture may include an empty or nonempty selection withthe nonempty selection having an associated source icon. The activationgesture also includes an origin and a direction. Upon detecting theactivation gesture, a target region is determined according to theactivation gesture. Target icons are selected from those remote iconswithin the target region. The selected target icons are temporarilydisplayed in proximity to the activation gesture's location until anaction dismissing the target icons is detected. The target icons may beselected according to their ability to respond to and operate on thecontent represented by the source icon. Thus, Baudisch presents asolution to the problem of accessing remote content from a currentworking location by temporarily displaying remote content in theproximity of the working area in response to a user's gesture indicatingthat the remote content should be temporarily relocated. One problemwith Baudisch's method is that possible targets are only filtered basedon compatibility with the dragged or source object. This can result inmany possible targets.

According to embodiments, additional methods are provided to filter orprune the number of candidate target objects to be temporarily relocatedfrom a remote area to a working area on a display screen or surface.According to one embodiment, filtering of remote content is performedaccording to recency of last use. Objects most recently used areselected as possible targets. According to another embodiment, filteringof remote content is linked to a current project. That is, projectrelated objects are selected. These can be determined based on pre-setobject categories, or determined based on which objects have been openedsimultaneously, or which objects have had content copied to one anotherpreviously. According to another embodiment, filtering is performedbased on similarity of name to the dragged object. For example, anobject named “Peters_Proposal.doc” would naturally fit with a documentcalled “Peters_Imagejpg.” According to another embodiment, objects thatscore low on one or more of these filtering metrics can either beexcluded entirely from the targeted objects or can be de-emphasized(e.g., by reducing their size, positioning them further away from thecursor, making them transparent, etc.).

A further aspect of the “screen real estate problem” is that of enablingusers to drag objects large distances. While Baudisch's method may beuseful for dragging one object to another object (e.g., a file onto afolder), it is not useful for general positioning tasks (e.g., draggingan image from one side of a tabletop display to another side of thetabletop display). Thus, especially for large displays, methods forenabling users to drag objects large distances are desired. According toone embodiment, a method for dragging objects large distances isprovided through multiplying or magnifying the effect of a dragoperation. According to this embodiment, if a user physically drags anobject presented on a display screen or surface a distance of x units ina selected direction, the object actually moves x*y units in thatdirection, where y>1. In other words, the drag operation is multipliedor magnified. Multiplied or magnified dragging may be implemented inseveral ways, as will be described below, depending on the configurationof the computer system 300.

With respect to the case of mouse/keyboard interaction, a toggle key onthe keyboard, such as the control or alt, key, may be selected by a userto indicate whether the user wants to have drag operations magnified.While the key is held down, the selected object moves at a faster speedduring the drag operation than usual. This speed can depend solely onthe speed at which the mouse travels, or it can depend on other factors.These other factors can include: the size of the entire screen; the sizeof the current window; and, the physical distance a mouse would need tobe moved to virtually traverse the cursor across either the window orthe screen.

With respect to the case of touch sensitive surface or display surfaceinteraction, refer to FIGS. 8 and 9. FIG. 8 is a screen captureillustrating a presentation 800 of an object 810 at an initial location811 prior to a magnified drag operation in which hand icons 501, 502 areused to indicate the locations 801, 802 of a user's fingers 701, 702 ona touch sensitive display surface 340 in accordance with an embodiment.FIG. 9 is a screen capture illustrating a presentation 900 of the object810 of FIG. 8 at a final location 911 after the magnified drag operationis performed in which hand icons 501, 502 are used to indicate thelocations 901, 802 of a user's fingers 701, 702 on the touch sensitivedisplay surface 340 in accordance with an embodiment. On touch-sensitivetabletop devices and display surfaces with the capacity to detecttwo-handed input, multiplied dragging can be performed by a user firstpressing a finger 701, 702 from each hand 501, 502 onto an object 810 atan original location 811 presented on the display 340. As shown in FIG.8, the locations 801, 802 of the first and second fingers 701, 702 onthe display surface thus initially correspond to the original location811 of the object 810. Next, the user drags his or her first finger 701in the desired direction of the drag operation to a final location 901for the finger as shown in FIG. 9. The second finger 702 stays at theoriginal location 811, 802. The actual distance between the fingers x(920 in FIG. 9) is multiplied by a factory to give an actual distancethe object travels x*y (930 in FIG. 9) in the desired direction of thedrag operation. The final location 911 for the object 810 is shown inFIG. 9. The motion by the user is similar to what a user would performif he or she were stretching a rubber band between a finger on eachhand. The use of two fingers 701, 702 (or hands 501, 502) is to indicateto the system 300 that a magnified drag is intended, as opposed to anormal drag operation, which would be performed using only one finger(or hand).

According to one embodiment, once the user has performed the multiplieddrag using a first finger 701 (or hand 501), as shown in FIGS. 8 and 9,by keeping his or her second finger 702 (or hand 502) in contact withthe display screen, the user may now perform fine positioning of theobject 810 by using this second finger 702 (or hand 502). In thisembodiment, movement of the second finger 702 in the vicinity of theorigin 811 of the drag operation will have a corresponding non-magnifiedimpact on the positioning of the object 810 in the target area 911. Inthis way, the first finger 701 may be used for rough positioning of theobject 810 while the second finger 702 may be used for subsequent finepositioning of the object 810.

Yet another aspect of the “screen real estate problem” is that ofindicating to users the location and nature of off-screen objects. In arecent paper by Baudisch and Rosenholtz (Baudisch, P. and R. Rosenholtz,“Halo: A Technique for Visualizing Off-Screen Locations”, Proceedings ofACM Conference on Human Factors in Computing Systems (CHI) 2003, FortLauderdale, Fla., pp. 34-43), which is incorporated herein by reference,a “halo” method for indicating the location of off-screen objects tousers is described. In this method, off-screen objects are surroundedwith rings that are just large enough to reach into the border region ofthe display window. From the portion of the ring that is visibleon-screen, a user can infer the off-screen location of the object at thecenter of the ring. One problem with this solution, of course, is thatwhile the location of the off-screen object is indicated to the user,the nature of that object is not. That is, the user cannot see theobject itself.

This problem also occurs in EPS applications. For example, if a fisheyelens is applied to an original image (e.g., a map) to generate adetail-in-context presentation and the lens stays fixed at its originallocation in the image, then panning can cause the lens to moveoff-screen where it may be lost to the user. On the other hand, if thelens remains stationary with respect to screen coordinates, then panningwill cause the contents displayed in the lens to change. According toone embodiment, the lens may present the detailed information for thelocation in the original image to which is was originally applied whileproviding awareness as to what objects are located off-screen. Accordingto this embodiment, lens folding is used to provide off-screen awarenessof objects to which lenses have been applied. In particular, lensfolding is used to the keep the focal region of the lens applied to anobject-of-interest on-screen at the border of the viewing area.

FIGS. 10 and 11 are screen captures illustrating off-screen awarenessvia lens folding. FIG. 10 is a screen capture illustrating apresentation 1000 in which first and second lens 1010, 1011 have beenapplied to an original image in accordance with an embodiment. In FIG.10, each lens 1010, 1011 has a respective focal region 1020, 1021 whichprovides detail for respective objects-of-interest (e.g., buildings) inthe original image. FIG. 11 is a screen capture illustrating apresentation 1100 in which lens folding has been applied to provideoff-screen awareness of selected objects-of-interest in FIG. 10 inaccordance with an embodiment. In FIG. 11, the presentation 1000 of FIG.10 has been panned downward and to the right. This panning wouldnormally have caused the second lens 1011 and the object to which it wasapplied to move totally off-screen. However, the second lens 1011 hasbeen folded such that its focal region 1121 remains on-screen at theborder 1101 of the presentation 1100. Thus, the content of the focalregion 1021 of the second lens 1011 remains visible to the user.

Advantageously, with this embodiment, no matter how far a lensed objectmoves off-screen due to panning, etc., at least a portion of it (e.g.,the portion in the focal region 1021) remains visible to the userthrough folding of the applied lens 1011. The focal region 1021 of thefolded lens 1011 may be considered as a geographic bookmark in such apresentation 1100. This provides a variety of additional advantages asfollows. Firstly, the object-of-interest is always visible (i.e., in thefocal region 1021 of the folded lens 1011). In dynamic data situations,the state of multiple separate objects can be tracked. Second, thedirection of the object-of-interest from the current view orpresentation is known at all times. That is, the object appearson-screen on the side of the view 1101 that points in the direction ofthe actual object off-screen.

This method of providing off-screen awareness may be varied. Accordingto one embodiment, off-screen objects that are closer to the border 1101of the on-screen presentation 1100 than other off-screen objects mayhave the focal regions 1021 of their folded lenses 1011 emphasized. Forexample, the focal regions 1021 for closer objects can be made largerwhile those of further objects can be made smaller, the focal regions1021 for closer objects can be made less transparent while those offurther objects can be made more transparent, etc. Objects can also beemphasized in various other ways in order to draw attention to objectsdetermined to be of greater interest.

According to another embodiment, the object-of-interest (i.e., the focalregion 1021 of the folded lens 1011) can function as a tab or bookmarkthat a user may select to automatically navigate to theobject-of-interest off-screen. Thus, navigation between different lensedpoints can be facilitated by the use of these bookmarks. For example, auser can click on the focal region 1021 of a lens 1011 causing the viewto scroll such that the lens 1011 belonging to that focal region 1021moves to the center of the screen. In effect, scrolling from thepresentation 1100 of FIG. 11 back to the presentation 1000 of FIG. 10.Alternately, controls can be attached to lens foci (e.g., via the GUI400) for allowing users to initiate a similar scroll-to-focus operation.

The above described method (i.e.; with respect to FIG. 5) may besummarized with the aid of a flowchart. FIG. 12 is a flow chartillustrating operations 1200 of software modules 331 within the memory330 of a data processing system 300 for generating a presentation 500 ofa region-of-interest in an original image for display on a displaysurface 340, in accordance with an embodiment.

At step 1201, the operations 1200 start.

At step 1202, a lens 410 for the region-of-interest is established, thelens 410 having a focal region 420 with a magnification for theregion-of-interest at least partially surrounded by a shoulder region430 across which the magnification varies to provide a continuoustransition from the focal region 420 to regions outside the lens.

At step 1203, a first signal is received for selecting the shoulderregion 430.

At step 1204, while receiving the first signal, a second signal isreceived for selecting the focal region 420 and for adjusting a positionof the focal region 420 relative to the shoulder region 430 to define adegree and a direction of a folding of the focal region 420 over theshoulder region 430 for the lens 410.

At step 1205, the lens 410 is applied to the original image to producethe presentation 500.

At step 1206, the operations 1200 end.

The display surface 340 may be a touch sensitive display surface and themethod may further include the step of receiving the first and secondsignals from the touch sensitive display surface touched by a user. Themethod may further include the step of receiving the first and secondsignals from a touch sensitive surface input device touched by a user.The first signal may be for selecting the shoulder region 430 and foradjusting a position of the shoulder region 430 relative to the focalregion 420 to define the degree and the direction of the folding. Themethod may further include the step of displaying the presentation 500on the display surface 340. The lens 410 may be a surface. The focalregion 420 may have a size and a shape and the method may furtherinclude the step of receiving one or more signals to adjust at least oneof the size, shape, and magnification of the focal region 420. Themethod may further include the step of receiving the one or more signalsthrough a graphical user interface (“GUI”) 400 displayed over the lens410. The GUI 400 may have means for adjusting at least one of the size,shape, and magnification of the focal region 420. At least some of themeans may be icons. The means for adjusting the size and shape may be atleast one handle icon 481, 481 positioned on the perimeter 421 of thefocal region 420. The means for adjusting the magnification may be aslide bar icon 440, 441. The display surface 340 may be a touchsensitive display surface and the method may further include the step ofreceiving the one or more signals from the touch sensitive displaysurface touched by a user. The method may further include the step ofreceiving the one or more signals from a touch sensitive surface inputdevice touched by a user. The shoulder region 430 may have a size and ashape and the method may further include the step of receiving one ormore signals through a GUI 400 displayed over the lens 410 to adjust atleast one of the size and shape of the shoulder region 430, wherein theGUI 400 has one or more handle icons 491, 492 positioned on theperimeter 411, 412 of the shoulder region 430 for adjusting at least oneof the size and the shape of the shoulder region 430. And, the step ofapplying 1205 may further include the step of displacing the originalimage onto the lens 410 and perspectively projecting the displacing ontoa plane 201 in a direction 231 aligned with a viewpoint 240 for theregion-of-interest.

While these techniques are primarily discussed as a method, a person ofordinary skill in the art will understand that the apparatus discussedabove with reference to a data processing system 300, may be programmedto enable the practice of the methods. Moreover, an article ofmanufacture for use with a data processing system 300, such as apre-recorded storage device or other similar computer readable mediumincluding program instructions recorded thereon, may direct the dataprocessing system 300 to facilitate the practice of the methods. It isunderstood that such apparatus and articles of manufacture also comewithin the scope of the techniques described herein.

In particular, the sequences of instructions which when executed causethe method described herein to be performed by the data processingsystem 300 of FIG. 3 can be contained in a data carrier productaccording to one embodiment. This data carrier product can be loadedinto and run by the data processing system 300 of FIG. 3. In addition,the sequences of instructions which when executed cause the methoddescribed herein to be performed by the data processing system 300 ofFIG. 3 can be contained in a computer software product according to oneembodiment. This computer software product can be loaded into and run bythe data processing system 300 of FIG. 3. Moreover, the sequences ofinstructions which when executed cause the method described herein to beperformed by the data processing system 300 of FIG. 3 can be containedin an integrated circuit product including a coprocessor or memoryaccording to one embodiment. This integrated circuit product can beinstalled in the data processing system 300 of FIG. 3.

The embodiments described above are intended to be examples only. Thoseskilled in the art will understand that various modifications of detailmay be made to these embodiments.

1. A method comprising: receiving a dragging signal from a mouse to dragan object on a display, wherein the dragging signal represents aphysical dragging having a first distance; and in response to receivingthe dragging signal, alternatively: moving the object a second distanceon the display if a signal from a key on a keyboard was not receivedwhile the dragging signal was being received, or moving the object athird distance on the display if the signal from the key on the keyboardwas received while the dragging signal was being received; wherein thethird distance is different than the second distance.
 2. The method ofclaim 1, wherein the third distance is greater than the second distance.3. The method of claim 1, wherein a speed at which the object is moveddepends on a speed at which the mouse travels.
 4. The method of claim 1,wherein a speed at which the object is moved depends on at least one ofa size of the display, a size of a window, or a physical distance themouse would need to be moved to traverse a cursor across either thedisplay or the window.
 5. At least one computer-readable storage devicecomprising instructions that, responsive to being executed by a dataprocessing system, cause the data processing system to performoperations comprising: receiving a dragging signal from a mouse to dragan object on a display, wherein the dragging signal represents aphysical dragging having a first distance; and in response to receivingthe dragging signal, alternatively: moving the object a second distanceon the display if a signal from a key on a keyboard was not receivedwhile the dragging signal was being received, or moving the object athird distance on the display if the signal from the key on the keyboardwas received while the dragging signal was being received; wherein thethird distance is different than the second distance.
 6. The at leastone computer-readable storage device of claim 5, wherein the thirddistance is greater than the second distance.
 7. The at least onecomputer-readable storage device of claim 5, wherein a speed at whichthe object is moved depends on a speed at which the mouse travels. 8.The at least one computer-readable storage device of claim 5, wherein aspeed at which the object is moved depends on at least one of a size ofthe display, a size of a window, or a physical distance the mouse wouldneed to be moved to traverse a cursor across either the display or thewindow.
 9. A method comprising: providing an object display signal todisplay an object in a first region of a touch sensitive display;receiving a first touching signal from the touch sensitive display,wherein the first touching signal represents a physical touching in thefirst region of the touch sensitive display; receiving a second touchingsignal from the touch sensitive display, wherein the second touchingsignal represents a physical touching in the first region of the touchsensitive display; while the second touching signal is being receivedfrom the first region of the touch sensitive display, detecting amovement of the first touching signal in a first direction and at afirst rate of speed away from the first region of the touch sensitivedisplay; and while detecting a movement of the first touching signal,changing the object display signal to move the object on the touchsensitive display at a second rate of speed in the first direction awayfrom the first region, wherein the second rate of speed is differentfrom the first rate of speed.
 10. The method of claim 9, wherein thesecond rate of speed is greater than the first rate of speed.
 11. Themethod of claim 10, further comprising: after detecting the movement ofthe first touching signal, detecting a movement of the second touchingsignal in a second direction and at a third rate of speed away from thefirst region of the touch sensitive display; and while detecting amovement of the second touching signal, changing the object displaysignal to move the object on the touch sensitive display at a fourthrate of speed in the second direction away from the first region,wherein the fourth rate of speed is different from the second rate ofspeed.
 12. The method of claim 11, wherein: the second rate of speed isgreater than the first rate of speed; and the fourth rate of speed isless than the second rate of speed.
 13. The method of claim 11, whereinsaid detecting a movement of the second touching signal is performedwhile detecting the first touching signal.
 14. The method of claim 9,wherein: the first touching signal further represents a touching of thetouch sensitive display by a first finger; and the second touchingsignal further represents a touching of the touch sensitive display by asecond finger.
 15. At least one computer-readable storage devicecomprising instructions that, responsive to being executed by a dataprocessing system, cause the data processing system to performoperations comprising: providing an object display signal to display anobject in a first region of a touch sensitive display; receiving a firsttouching signal from the touch sensitive display, wherein the firsttouching signal represents a physical touching in the first region ofthe touch sensitive display; receiving a second touching signal from thetouch sensitive display, wherein the second touching signal represents aphysical touching in the first region of the touch sensitive display;while the second touching signal is being received from the first regionof the touch sensitive display, detecting a movement of the firsttouching signal in a first direction and at a first rate of speed awayfrom the first region of the touch sensitive display; and whiledetecting a movement of the first touching signal, changing the objectdisplay signal to move the object on the touch sensitive display at asecond rate of speed in the first direction away from the first region,wherein the second rate of speed is different from the first rate ofspeed.
 16. The at least one computer-readable storage device of claim15, wherein the second rate of speed is greater than the first rate ofspeed.
 17. The at least one computer-readable storage device of claim15, wherein the instructions, responsive to being executed by the dataprocessing system, cause the data processing system to performoperations further comprising: after detecting the movement of the firsttouching signal, detecting a movement of the second touching signal in asecond direction and at a third rate of speed away from the first regionof the touch sensitive display; and while detecting a movement of thesecond touching signal, changing the object display signal to move theobject on the touch sensitive display at a fourth rate of speed in thesecond direction away from the first region, wherein the fourth rate ofspeed is different from the second rate of speed.
 18. The at least onecomputer-readable storage device of claim 17, wherein the second rate ofspeed is greater than the first rate of speed.
 19. The at least onecomputer-readable storage device of claim 18, wherein the fourth rate ofspeed is less than the second rate of speed.
 20. The at least onecomputer-readable storage device of claim 15, wherein: the firsttouching signal further represents a touching of the touch sensitivedisplay by a first finger; and the second touching signal furtherrepresents a touching of the touch sensitive display by a second finger.